What Makes Efficient Windows

Energy efficiency is determined from measuring five different data points. Many customers seek efficient windows when looking to replace theirs. The United States Department of Energy’s blue-and-yellow Energy Star label helps show the energy efficiency of products. For windows to gain the Energy Star seal, officials analyze five measurements.

First they take into account U-factor of the window assembly. The lower the U-factor, the greater a window’s resistance to heat flow and the better its insulating properties. U-factors range from 0.20 to 1.20. Windows must have a U-factor of 0.3 or less to qualify for tax credits.

Secondly, they look at the Solar Heat Gain Coefficient or the SHGC. This refers to the solar radiation a window or door allows inside. Customers should seek the lowest possible SHGC rating in warm climates to minimize air conditioning use. In cooler climates, customers should look for a slightly higher number so that the sun can help heat the home in the winter. SHGC ranges from 0 to 1 and a window must have a 0.3 or less to qualify for tax credits.

Next officials evaluate the visible transmittance, which is the amount of light a window allows to pass through. Numbers range from 0 to 1 and there are no tax credit qualifications with this.

Then air leakage is measured. The number, expressed in cubic feet per minute per square foot of a window or door area represents the amount of air that window or door allows passing through. There is neither range nor qualifications for tax credit, but .03 is the standard building code.

Finally, officials measure the condensation resistance. The condensation resistance measures how much moisture a window or door allows to build up on the surface or between glazing layers. While there are no tax credit qualifications for this either, the numbers range from 1 to 100. The lower the number, the more condensation the window or door allows to build up.

If you are looking to replace your old windows or doors, now is a great time to do so! The tax credit for energy efficient windows and doors has been extended through the end of 2016. Call today and speak with one of our window installation experts.

Schedule Today For Our Integrity Pricing Promise & Free In-Home Estimate

Keller Window Door003 - What Makes Efficient Windows

Contact Us for all your window needs.

LOCATION

87 Grasso Plaza #246
St. Louis, MO 63123

(314) 399-2001

Areas Served - St. Louis, Chesterfield, Town & Country, Clayton, St. Charles, Wildwood. University City, O'Fallon

 

Copyright ©  2018 Keller Window & Door, LLC | All Rights Reserved |  Privacy Policy
Some photos reproduced under license from Andersen Corporation for a specific & limited purpose.